An exemplary type of printer is an inkjet printer. In this regard, as inkjet printing technology increasingly achieves higher performance standards, inkjet printers are becoming more widely used for high-quality imaging, particularly in graphic arts applications, color printing, and proofing. In comparison with inexpensive “desktop” color printing applications, high-quality imaging applications require considerably more control over printing factors such as dot registration, dot size, ink density, color gamut and overall repeatability. Among digital color prepress systems, the “REALIST”™ printer (manufactured by IRIS Graphics, Inc., located in Bedford, Mass.) and the “SILVER REED”™ printer (manufactured by Silver Seiko Ltd., located in Tokyo, Japan) exemplify printers that achieve high-quality imaging using inkjet technology.
To serve the needs of this high-quality imaging market, manufacturers of inkjet printers and suppliers of consumable components, head-cleaning chemicals, inks, and receiver media manufacture these systems and consumables to exacting standards. Consumable inks used in these applications are tested to provide sensitometric performance within tight tolerances. Consumable receiver media (such as paper, film, textiles, and other substrates) are expected to be manufactured within a narrow range of variability for color, thickness, coating, and other characteristics. Printheads, which may be considered disposable (therefore considered as “consumable”) with some systems, are precision-fabricated to provide repeatable performance, print to print. The need for high quality forces manufacturers of inkjet consumables to test and market consumable products that, in part, compensate for variability allowed with other consumables. This drives up the cost of consumables and increases the overall cost of operation to the owner of the inkjet printer.
To maintain high quality standards, consumables manufacturers routinely test and certify their products for performance within a required range. Consumable inks, for example, are characterized sensitometrically to provide repeatable response within a controlled color space. Inks may be differently formulated based on dye or pigment quality, intended use, or variable manufacturing conditions. While manufacturers collect and store this type of detailed consumables information, such information is not generally available to the end user or to the inkjet printing system itself. If such information were available, it could be used by control logic within the inkjet printer to optimize processing and printing and improve the overall level of imaging performance achieved by the inkjet printer. And if detailed information from manufacture were available on each type of consumable loaded in the printer, a control program on the printer could compensate for combinations of consumables, allowing the printer to adjust its imaging parameters accordingly.
Conventional inkjet printers have been adapted to identify the types of ink and paper loaded. U.S. Pat. No. 5,812,156 (Bullock, et al.) discloses use of a memory IC integrated into an ink cartridge or printhead and used to store usage information and data regarding variables such as ink type, manufacture date and batch, and performance. Here, a separate electrical connector is disclosed for making connection with memory circuitry when the ink cartridge is inserted into the printer. However, the requirement for electrical connection to the inkjet cartridge places demands not only on the design of the cartridge itself, but also on the design of the printer, because a corresponding connector must be provided to mate with the connector on the ink cartridge. Over time, electrical contacts that require regular connection and disconnection, such as occurs when an expended ink cartridge is removed and a new one inserted, provide a potential source for problems. Electrical contacts are known to break, collect dirt, corrode, or become misaligned, for example. This type of design solution may be workable with a low-volume desktop inkjet printer that employs a cartridge-based ink supply. However, large-capacity inkjet printers such as the “REALIST”™ and “SILVER REED”™ printers noted hereinabove use ink supplied from bottles, where direct electrical connection to the ink source is not easily provided.
U.S. Pat. No. 5,365,312 (Hillman, et al.) also discloses use of a memory associated with an ink reservoir for an inkjet printer. Here again, the solution disclosed requires an electrical connection with the memory component, which requires redesign of conventional ink bottle packaging to include a memory chip and a connector.
For use with such large-capacity printers, it would be beneficial to provide memory integrally attached to the ink consumable, where the memory could then be used to store manufacturing, performance, and usage information. It would be especially advantageous if redesign of packaging and addition of a separate connector were not required.
International patent WO 98/52762 (Purcell, et al.) discloses an inkjet printer in which memory circuits are disposed within ink and paper consumables, including memory connected with an RF transponder that is attached to a roll of paper media. Contactless communication, using an RF transceiver built into the inkjet printer, provides added advantages in situations where it would be difficult to maintain physical electrical contact with a rotating paper roll during operation.
In addition to consumable inks and paper used directly for imaging, a large-format inkjet printer may also include consumable fluid for printhead cleaning. A printhead in such a printer can be used with different types of ink and, correspondingly, can require different cleaning fluid formulations. Memory attached to the cleaning fluid consumable can be used to identify the formulation of the cleaning fluid consumable and to store usage information. Such information could also be used by the printer to make sure that the proper cleaning fluid is installed for the ink currently being used. In addition, because these fluids may include solvents or chemicals that might require collection and return to a disposal facility after use, it would be beneficial to identify the specific formulation of waste cleaning fluid collected in a waste bottle or other container. This same advantage would apply for waste inks, in systems that employ a “continuous-flow” output, in which unneeded droplets of ink are deflected to a waste container.
In the memory solutions disclosed above, usage data is currently obtained by counting. In the simplest implementations, printer logic counts the number of prints generated and stores these values in memory to maintain a rough estimate of consumables usage. Or, printer logic directly counts the number of ink droplets expelled from a specific ink reservoir. Tracking usage in this manner has some inherent disadvantages, because some type of averaging and estimation must be used. Moreover, for cleaning fluid consumables, a counting method of this type could only provide a gross estimation of usage and of fluid remaining. It would be advantageous if a consumable device had a built-in sensing mechanism that, acting in cooperation with integrally connected memory components, accurately indicated the amount of a consumable used or remaining. Conventional sensing methods include mechanical level-sensing, but do not integrally couple level-sensing with attached memory components.
A printhead may be used with specific inks or with specific receiver media and, in some inkjet printers, is considered a consumable item. There may be instances where usage data stored with the printhead is useful for maintaining reliable printer operation. Previously mentioned U.S. Pat. No. 5,812,156 also discloses a memory circuit attached to a removable printhead. Electrical contacts to the memory circuit are provided in the printhead interface to the printer. This allows identification of printhead type, provided that the printhead is installed in the printer apparatus.
In an inkjet printer, the ability of control logic to access detailed information on consumable receiver media, inks, and cleaning fluids, and on the printing hardware itself, helps to optimize the writing process and provides tools for maximizing image quality. Thus it can be seen that there is a need for an inkjet printer that is adapted to sense types of consumable receiver media, inks, cleaning chemicals, and printhead. The capability of the printer to perform this type of sensing without making physical contact with the consumable package would present cost, ease of use and reliability advantages.